I have a dual-boot machine with XP Pro and FC5 and I did my partition much like Gethyn said.
On a 80 GB drive, I have:
/dev/hda1 NTFS Windows C:\ 20 GB
/dev/hda2 ext3 Linux /boot 80 MB
/dev/hda3 FAT32 Windows E:\ 30 GB
/dev/hda5 ext3 Linux / 10 GB
/dev/hda6 swap Linux swap 512 MB
/dev/hda7 ext3 Linux /home 14 GB
I use a LVM (formatted in jfs) on my MythTV server, where I have created a 532 GB partition (from a 250 GB Seagate and a 300 GB Western Digital) for my multimedia files (MPEG-2 and DivX videos, pictures, MP3 music files, etc.).
The LVM and the more 'exotic' file systems (reiser, jfs, xfs) are sometimes better suited for large data partitions and large files than your basic ext3 filesystem. For your basic partition needs , stick to something well proven and tested.